code: def _init_vgg16_extra_layers(self):
      self.conv6 = Conv2D(1024, [3, 3], rate=6, name="conv6")
      self.conv7 = Conv2D(1024, [1, 1], name="conv7")
      self.conv8_1 = Conv2D(256, [1, 1], name="conv8_1")
      self.conv8_2 = Conv2D(512, [3, 3], stride=2, name="conv8_2")
      self.conv9_1 = Conv2D(128, [1, 1], name="conv9_1")
      self.conv9_2 = Conv2D(256, [3, 3], stride=2, name="conv9_2")
      self.conv10_1 = Conv2D(128, [1, 1], name="conv10_1")
      self.conv10_2 = Conv2D(
          256, [3, 3], padding="VALID", name="conv10_2"
      )
      self.conv11_1 = Conv2D(128, [1, 1], name="conv11_1")
      self.conv11_2 = Conv2D(
          256, [3, 3], padding="VALID", name="conv11_2"
      )
  
file_path: luminoth/luminoth/models/ssd/feature_extractor.py
imports: import sonnet
  import tensorflow
  from sonnet.python.modules.conv import Conv2D
  from tensorflow.contrib.layers.python.layers import utils
  from luminoth.models.base import BaseNetwork
label_desc: Use image node_id 2 for calling the SSDFeatureExtractor obj's underlying member method code with example usage: obj._init_vgg16_extra_layers() without return types